So I've been researching this to try and determine if it will help my hanging idle. I pulled the cover off last night, removed the diaphram and spring. So the small hole at about 7 or 8 o'clock is the one the I need to plug? I've read that people use, silicone, jb weld, a piece of a rubber o-ring, etc, what's worked the best for people. I just replaced my float bowl o-ring. I was looking at it last night and it looks like a piece of the old one is the perfect size to fit down in there. If I do go with an o-ring, thats it, no silicone to hold it? I guess I would like to try it out before I make it a perminant fix.

http://xr650r.us/xr6...faqtemp/ACV.htm


Go to the last post on that page,,that seems to be the best explanation I can find about blocking it.Forget all the other stuff about cutting the nipple off,,it's incorrect

and once again I'll say there is something wrong with the posting setup here. If I disable my Addblocker as the site seems to want me to do so I can use the non complex posting system I cannot copy and post links from other sites. This site does not seem to want to accept the copy and paste.

Whatever viglink.com is appears to be the issue. Pc starts working overtime as soon as it is allowed via the addblocker software.

put some rvt over the hole. On initial start and warm up the change is very noticable. I'm bummed I didn't have a chance to go out and ride it.

So didn't you use a piece of gasket material as the guy in that post I linked to said to use..Anyway I dunno if some goo over the hole would be adequate,,Personally I'd have used the gasket material and reversed the internals as he stated. Doesn't your bike have the hanging idle problem at startup??,,I'd have thought if blocking the ACV hole fixed it you'd know as soon as you fired the thing up..???

Not strictly true of course as I know with my XR600 with the slight hanging idle issue,,Can take a bit of time for it to exhibit the characteristics,,ie bike needs to get up to temperature.

Horri, on 23 January 2012 - 02:41 AM, said:

I was under the impression we were supposed to plug the hole in the back under the diaphram, not the hole on the cover with the o-ring. The dude in your thread you posted is plugging the hole where the little o-ring is on the cover right?

Can someone please help by clarifying which hole to plug? I'd like to get this right. Like I said in the earlier response, I plugged the hole in the back underneath the diaphram, the little hole is at about 7 oclock. I started the bike up and it was noticably different, the idle was not hanging. I did not get to ride it though. I've searched and searched and there is no clear explanation on what hole to plug.

http://www.thumperfaq.com/acv.htm

The above deals with the WRF450 Yamaha..I cannot imagine the XR to be radically different,,Read all the links although to me it's pretty well explained in the main body of the post..Turn the diaphragm around so the pin doesn't actuate the Aircut off pin which is inside the central hole. If that doesn't seem to work on your carb ,,ie,,not enough room left over with the diaphragm reversed to allow you to screw on the cover you are going to have to wait until a part I'm waiting for for the carb on my 600 turns up so I can have a proper look at what will work..If you can't wait the obvious thing to do is cut the nipple off your diaphragm and simply order another should it not work..They are only about $25.00 to replace..


God,,Talk about slow,,This site is just painful to deal with now,,very similar to ADV rider,,Scrolling's ridiculously slow,just seems to carry on scrolling for no reason as well as being slow at the actual scrolling,, pc's working overtime every time I come here..Even blocking all the crap extras has made no difference..Outta here..

IMO, the better choice would be to put all the ACV parts back in and find the real reason your idle is hanging...

HeadTrauma, on 24 January 2012 - 01:31 PM, said:

I understand your thinking, I don't like tinkering with stuff or doing unecessary mods. I completely disassembled the carb and cleaned it. My jetting is right on for an uncorked R. I've got no cables binding. What else can I do? I'd like to try this ACV mod to see how it works, if it doesn't I will put it back. Maybe I'm having trouble with it because I've been riding a 450X with an FCR carb. Maybe thats why the "hanging" idle is so noticable.

Does the idle return to normal if you help the carb close manually? Don't discount internal mechanical wear as a possible cause.

Sounds like quite a good mod though,,From my understanding of it after trolling through masses of stuff about it is it gives you a heap more engine braking,,contrary to what's written on some sites..That's gotta be good,,Love engine braking myself.

Horri, on 24 January 2012 - 11:42 AM, said:

I cant agree with you more. An old top fuel drag racer here in the US named Eddie Hill ran by a simple saying...if it ain't broke, don't fix it. I almost feel compelled to jump over to another forum.

Picture belows the Aircut orifice.

http://imageshack.us.../img0204sa.jpg/

Picture belows what I used to take it out of action,,
The copper thing is an old wooden boatbuilders rivet.
Picture below is of one shaped side.

http://imageshack.us...4/img0201k.jpg/


Pictures below is the rivets other shaped side

http://imageshack.us.../img0200tl.jpg/


Picture below is the Rivet on the aircut diaphragm

http://imageshack.us.../img0202aj.jpg/

Picture below is a side on of the Rivet on the Aircut

http://imageshack.us...2/img0203l.jpg/

This did not seem to improve the slight high idle issue I had.
Tested and it's a fail,If anything the idle was higher and the engine
seemed to sound as if it was running rich..No increase in popping on deceleration
with the mod,,In fact no discernable popping.

All I did was put the Rivet over the pin which then stops the pin
entering the hole in the aircut orifice enough to actuate the internal mechanism

Make of it what you will,,My bikes back to the normal aircut system
and is running well.

The above was posted on one of my other more powerful Desktop pcs.,,My old Laptop can no longer handle this site,,I am still running the anti script software and the only problem is the horrible edit function with all sorts of code everywhere in it, Once I sort that I will use this Desktop pc for posting here. Above was all copied and pasted from a pre made document on my Desktop as the edit system is just bent with Script Sentry running on Firefox. Happy biking .

Horri, on 27 January 2012 - 06:13 PM, said:

Great pictures Horri, thanks! So I followed Borynacks write up the best that I could and decided he must be talking about the hole behind the diaphram, the one at the bottom of your first picture. In the bottom of his write he said don't mess with the diaphram so I didn't. I put some RVT over it and let it sit for a few days. Got it out tonight and rode around. No more hanging idle! It ran good...........once I got my pilot screw right. I had it out about 4 turns by mistake, didn't bottom it out all the way initially. Out 2.5 turns.

Great pictures Horri, thanks! So I followed Borynacks write up the best that I could and decided he must be talking about the hole behind the diaphram, the one at the bottom of your first picture.

So you mean you plugged the one that's at about the 8 oclock position if the carb was upright,,Didn't really look at that but seeing as the Aircuts pretty accessible I might try a plug in that and see what occurs. I couldn't tell with my effort whether the engine braking had improved as it's supposed to so I'll give your idea a shot tomorrow..,,My bikes actually idling pretty well at the moment but there's no harm in having another tinker,,Might just jam a short piece of pointed stick in it as the plug,,I can then use a small self tapping screw to pull it out if it's a fail or makes no difference,,No sense getting overly technical about the plug..,,,Though in saying that the hole size is kinda deceptive in that photo,,That 8 oclock hole is tiny,,,minor rethink required as no screw I have would be that puny though I have a good range of small radio internal type stuff..,,Bound to be something in my collection of "You never know when you might need it" stuff that'll be suitable..

Got out and rode it some more today. First putting around with the kids I noticed it got a little blubbery right off of idle but cleared up if I opened her up more. Came back and gave the pilot screw an extra half turn, so now I'm out 3 turns. Cleared it up some but still a little bit there. It clears up right away though. There are no other hesitations or hickups anywhere. Starts easy on the first kick. I ran up the road and went through the gears, held it open for a while at 75 mph, didn't even feel like it was breathing hard. I'm going to leave the ACV blocked off for a while I think.

Fair enough..Tried it about an hour ago using a small self tapping screw to block the hole at the 8 oclock position in the first picture,,Same results as when I used the Rivet end method,,Blubbery,,hard to start,,idle hanging,,conks out at attempted idle,,Exact opposite to your results., I'm done with the attempt at whatever the mods supposed to do,,Just does nothing for my bike,,Soon as I removed the screw,,one kick,,running..idles normal,,Call it a draw,,,

Horri, on 28 January 2012 - 08:27 PM, said:

bummer! 600's and 650R's have different carbs, maybe that has something to do with it??